Exemplary embodiments of the present disclosure relate to a spray nozzle for an attemperator and an attemperator including the same, and more particularly, a cooling water spray nozzle which is provided in equipment such as a steam boiler of a thermal power plant that uses high-temperature steam, and reduces or prevents high-temperature steam from being overheated and controls the temperature of the steam.
Generally, a boiler for power generation is provided with a superheater for generating high-temperature steam needed for a turbine. Steam generated from the superheater is supplied to the turbine through a steam transfer pipe. An attemperator is installed on the steam transfer pipe so as to control the temperature of supplied steam to a temperature required in the turbine.
FIG. 1 is a conceptual diagram of an attemperator 100.
The attemperator 100 is installed outside the steam transfer pipe 200 through which high-temperature steam is transferred. The attemperator 100 includes a fixed pipe 20 which is installed outside the steam transfer pipe 200 and a spray nozzle 10, which is supported on the fixed pipe 20 and inserted into the steam transfer pipe 200.
The spray nozzle 10 is fixed by the fixed pipe 20 and a first weld 101. The fixed pipe 20, into and to which the spray nozzle 10 is inserted and fixed, is fixed to the outer circumferential surface of the steam transfer pipe 200 by a second weld 102.
In the spray nozzle installed in the above-mentioned manner, vibration is generated by high-temperature and high-pressure steam flowing through the steam transfer pipe, and there is a problem in that a coupling portion of the spray nozzle may be damaged by a resonance phenomenon caused when the frequency of vortex shedding of steam that is generated around the spray nozzle matches the natural frequency of the spray nozzle.
In an effort to overcome this problem, a technique may be employed in which a diaphragm 30 is attached on the outer surface of the spray nozzle. The diaphragm 30 has elasticity and is interposed between the spray nozzle and the fixed pipe, thus mitigating vibrations of the spray nozzle. The diaphragm 30 is fixed to the outer surface of the spray nozzle by a third weld 103.
The spray nozzle having the diaphragm is assembled with the fixed pipe in such a way that the spray nozzle is force-fitted into the fixed pipe, whereby the diaphragm is supported in the spray nozzle and the fixed pipe with sufficient strength. Thereby, the diaphragm increases the natural frequency of the spray nozzle, thus mitigating vibration of the spray nozzle.
However, in the spray nozzle having the above-mentioned shape, there is high probability of thermal deformation in the spray nozzle during a process of attaching the diaphragm to the spray nozzle by welding, and there is also high probability of a defect occurring during the force-fitting operation. Furthermore, there are problems in that it is not easy to separate the conventional spray nozzle from the fixed pipe, and it is difficult to reuse the fixed pipe and the spray nozzle.